A smattering of reviews of the newly released HD7950 have arrived to the web as the card that many enthusiasts have been waiting for finally arrives. The card does not differ significantly from the HD7970 with 1,792 Stream Processors down from 2,048, 112 Texture Units versus 128, a core clock 125MHz lower at 800MHz and 5GHz effective on memory versus 5.5GHz for the HD7970. Apart from those changes it is still the same silicon and the same 4.31 billion transistors which raises hopes that a similar BIOS mod to the one which allowed you to turn some HD6950s into HD6970s will exist for this card as well. [H]ard|OCP's testing shows the card to be better than a GTX580 but not enough to be an upgrade for current owners of that card but anyone with the ~$450 and an older card would do well to consider this car.

You can also see Ryan's take on this card alone as well as how it scales in CrossFire in our review here.

"The new Radeon HD 7950 marks the launch of AMD's more affordable Radeon HD 7900 series GPU. The Radeon HD 7950 is priced to compete with the GeForce GTX 580. We'll look at performance in comparison to several video cards in single-GPU, dual-GPU CrossFireX, Eyefinity, and Overclocking to see where it truly lands."

Tahiti Gets Clipped

It has been just over a month since we first got our hands on the AMD Southern Islands architecture in the form of the Radeon HD 7970 3GB graphics card. It was then a couple of long weeks as we waited for the consumer to get the chance to buy that same hardware though we had to admit that the $550+ price tags were scaring many away. Originally we were going to have both the Radeon HD 7970 and the Radeon HD 7950 in our hands before January 9th, but that didn't pan out and instead the little brother was held in waiting a bit longer.

Today we are reviewing that sibling, the Radeon HD 7950 3GB GPU that offers basically the same technology and feature set with a slightly diminished core and a matching, slightly diminished price. In truth I don't think that the estimated MSRP of $449 is going to really capture that many more hearts than the $549 price of the HD 7970 did, but AMD is hoping that they can ride their performance advantage to as many profits as they can while they wait for NVIDIA to properly react.

Check out our video review right here and then continue on to our complete benchmarking analysis!!

Southern Islands Gets Scaled Back a Bit

As I said above, the Radeon HD 7950 3GB is pretty similar to the HD 7970. It is based on the same 28nm, DirectX 11.1, PCI Express 3.0, 4.31 billion transistor GPU and includes the same massive 3GB frame buffer as its older brother. The Tahiti GPU is the first of its kind of all of those facets but it has a few of the computational portions disabled.

If you haven't read up on the Southern Islands architecture, or Tahiti GPU based around it, you are missing quite a bit of important information on the current lineup of parts from AMD. I would very much encourage you to head over to our Radeon HD 7970 3GB Tahiti review and look over the first three pages as it provides a detailed breakdown of the new features and the pretty dramatic shift in design that Southern Islands introduced to the AMD GPU team.

[H]ard|OCP recently came out with two HD7970 reviews, one made by ASUS and one by XFX. The ASUS Radeon HD 7970 is currently one of the least expensive choices at $559 and runs at the default speeds of 925MHz and 1375MHz. It does ship with ASUS' GPU Tweak utility to allow for easy overclocking if you wish to push the card like [H] did, in their case to 1125MHz on the GPU core, and 1695MHz GDDR5.

The other choice is the XFX R7970 Black Edition which is a custom card, overclocked to 1GHz on the core and 1425MHz GDDR5 but costs $50 more than the offering from ASUS. At the out of the box speeds, XFX's card both draws less energy and runs much cooler and was silent compared to the ASUS offering. Even after [H] overclocked the card to 1125MHz core and 1575MHz GDDR5, which was the maximum possible using AMD's Overdrive, it was almost silent when running full out.

The decision seems to be how much it is worth to you to have a quiet card and if you are willing to find a way to overclock beyond what the Catalyst Control Center can manage.

"We have the new XFX R7970 Black Edition video card to evaluate, which is XFX's current flagship Radeon HD 7970 based video card. With a custom PCB, custom hardware components and custom cooling fan, will it take us to new heights in overclocking, or leave us wishing we had just purchased a "reference" card?"

If somehow you ended up feeling that Ryan missed something about the HD 7970 that was important to you, we offer a long enough list of HD 7970 reviews that you will find it somewhere. Come next week when these cards hit the market at about $800 apiece (the MSRP is $550USD so hope that number is inflated), you might want to know just how well the cards scale, assuming you are able to spend the better part of $2000 just on your graphics subsystem. The Guru of 3D has answered your Croesus-like desires by running two HD 7970's in CrossFire. The power usage turned out to be quite interesting, the total power used by two HD 7970s is comparable to that of a single HD 6970, which will at least help you save a bit on your PSU and electricity build. More important to most is the performance scaling, which Guru3D tested exhaustively and are happy to report scaling between 1.6 to 2 times the performance. Keep in mind you need huge resolutions to make this worth your investment, it takes a lot of money to play Battlefield 3 @ 2560x1600.

"We review the AMD Radeon HD 7970 in Crossfire. With two reference cards in-house, we figured well, you might be interested in some multi-GPU lovin from AMD.

Let's take it to the next level -- multi-GPU gaming in 2-way Crossfire mode."

With 2,048 stream processors, 3GB of GDDR5 memory, and DVI, HDMI and a pair of mini-Displayport outputs the new HD 7970 can support six displays and might even have the power to do it well. Internal reviews, which are to be taken with your daily allowance of NaCl, suggest a 70-90% jump in performance when compared to the previous generation of AMD GPUs. This all comes at a cost however, with a ~$700 price tag being predicted for the base model and unfortunately that is likely what you will get. Even though AMD opened up the specifications for their manufacturers, allowing them to set whatever clock speeds and cooling solutions they desired it seems that most companies opted to go with the reference model, at least for now. The other cost is power; the new 28nm process allows extremely low powered idling but as the card requires both an 8 pin and a 6 pin PCIe power connector you can be assured the card will use a lot of power when going full out, especially if you utilize the automatic 33% overclock that is enabled by the Powertune application mentioned by The Inquirer in their article.

"CHIP DESIGNER AMD has released the Radeon HD 7970 based on its Tahiti GPU chip.

AMD's Radeon HD 7970 is the first graphics board design based on its 28nm Southern Islands Tahiti GPU. The chip, which AMD claims has 4.3bn transistors, has been significantly changed from the previous Northern Islands generation Cayman Radeon HD 6970, has more on-chip cache and the firm claims it has greater overclocking headroom."

The First 28nm GPU Architecture

It is going to be an exciting 2012. Both AMD and NVIDIA are going to be bringing gamers entirely new GPU architectures, Intel has Ivy Bridge up its sleeve and the CPU side of AMD is looking forward to the introduction of the Piledriver lineup. Today though we end 2011 with the official introduction of the AMD Southern Islands GPU design, a completely new architecture from the ground up that engineers have been working on for more than three years.

This GPU will be the first on several fronts: the first 28nm part, the first cards with support for PCI Express 3.0 and the first to officially support DirectX 11.1 coming with Windows 8. Southern Islands is broken up into three different families starting with Tahiti at the high-end, Pitcairn for sweet spot gaming and Cape Verde for budget discrete options. The Radeon HD 7970 card that is launching today with availability in early January is going to be the top-end single GPU option, based on Tahiti.

Let's see what 4.31 billion transistors buys you in today's market. I have embedded a very short video review here as well for your perusal but of course, you should continue down a bit further for the entire, in-depth review of the Radeon HD 7970 GPU.

Southern Islands - Starting with Tahiti

Before we get into benchmark results we need to get a better understanding of this completely new GPU design that was first divulged in June at the AMD Fusion Developer Summit. At that time, our own lovely and talented Josh Walrath wrote up a great preview of the architecture that remains accurate and pertinent for today's release. We will include some of Josh's analysis here and interject with anything new that we have learned from AMD about the Southern Islands architecture.

When NVIDIA introduced the G80, they took a pretty radical approach to GPU design. Instead of going with previous VLIW architectures which would support operations such as Vec4+Scalar, they went with a completely scalar architecture. This allowed a combination of flexibility of operation types, ease of scheduling, and a high utilization of compute units. AMD has taken a somewhat similar, but still unique approach to their new architecture.

The 28nm process is causing a lot of problems for tech companies especially AMD who have cancelled the follow ups to Llano and Ontario, Krishna and Wichita. Not only have they cancelled the chips but they have switched from GLOBALFOUNDRIES to TSMC to have the replacement chips designed and fabbed. This is most likely because of the low yields that have been coming out of GLOBALFOUNDRIES with Llano, AMD's most successful recent design. The low volumes hurt AMD's market share since many companies would not base a product line on a chip that might not be around in volume. As well a deal is expiring in January which had AMD only paying for good dies, instead of the more usual practice of paying for the entire wafer and dealing with the bad dies as they come

That move might not be as successful as AMD hopes when you look at this article from DigiTimes. As it turns out TSMC is concerned about their ability to meet the demand for 28nm chips from their customers. It is not just AMD that is turning to TSMC for 28nm, Altera, NVIDIA, Qualcomm and Xilinx are already customers and Broadcom, LSI Logic and STMicroelectronics may join that crowd. With so many customers utilizing the same process even small problems on TSMC's lines could lead to big drops in available chips. Let us hope the days of the 40nm problems at TSMC never come back.

"Taiwan Semiconductor Manufacturing Company (TSMC) continues to see orders heat up for advanced 28nm technology, despite a general slowdown in the semiconductor industry, according to industry sources. Order visibility has stretched to about six months, said the sources.

TSMC is expected to see 28nm processes account for more than 2% of company revenues in the fourth quarter of 2011. The proportion will expand further to over 10% in 2012, as more available capacity coupled with rising customer demand boost the output, the sources indicated."

While most enthusiasts are living up to the name as far as the build up to the coming GPU refreshes from both AMD and NVIDIA is concerned, the manufacturers are quite the opposite. There are several probable reasons for this attitude, not least of which are the number of HD 6570s and GTS 450s that are still in their stock. Remember those cards from back in the spring of this year, which were the high end of a huge range of GPUs from both companies spanning $20 to either side of $100? Think that with the current generation of Llano and SandyBridge that any knowledgeable person is going to purchase one, let alone when you consider how close the release of next generation of APUs is? The two major players in the discrete GPU market not only updated the top end of their cards quickly over the past several quarters there was a widening of the market which saw current generation cards available from ~$75 to ~$750 with some segments separated by as little as $10. That translates to huge inventories at the manufacturer level which they then have to convince resellers and retailers to purchase for stock to sell to the consumer and many of those cards are still sitting there collecting dust. No wonder these same companies are leery of purchasing more stock before finding a way to recover some profit from the stock they have now.

To make things even worse there exist doubts about the 28nm process from TSMC, which DigiTimes discusses here. While AMD is still claiming delivery of HD7000 family cards before the coming year, the troubles that NVIDIA seems to be having with the same process concerns those who need to be able to buy large volumes of chips in order to turn a profit selling graphics cards. Even worse is the realization that the first cards NVIDIA will be releasing are simply a die shrink, without architectural changes. When two companies go to the same source for the same thing and one reports getting apple cider and the other apple vinegar, you really have to start to wonder what is really going on.

"While Nvidia and AMD are poised to use Taiwan Semiconductor Manufacturing Company's (TSMC's) 28nm technology to produce the GPUs Kepler and Southern Islands respectively, most Taiwan-based graphics card makers hold a conservative attitude about the new GPUs with some makers cautiously watching the market status before making any further decisions, according to industry sources.

Compared to the makers' eagerness for the previous-generation GPUs, graphics card makers are rather conservative about the upcoming 28nm chips due to concerns such as TSMC's weak 40nm process yield rate issues may re-occur in its 28nm process and weakening demand for graphics cards and lower-than-expected gross margins."

Woe is AMD, as it becomes ever more obvious that Llano is not giving good yields at GLOBALFOUNDRIES. Back in July the market noticed that while the new Llano chips were great at providing good enough graphics for a great price, they were very hard to find. As a consumer you might be able to find a notebook to purchase for yourself but as a reseller who needs to buy processors in the thousands before considering that chip as a part of the new product line up you have been out of luck. According to DigiTimes this will change in 2012 with the arrival of Trinity which will still use GLOBALFOUNDRIES 32nm process, turning to TSMC for the 28nm graphical portion. The previous hope that the supply problems would be solved in September were obviously a little too optimistic.

"Supply of AMD's Llano APUs, affected by Globalfoundries's lower-than-expected 32nm yield rates, has been significantly limited and is unlikely to recover until the company's upcoming Trinity arrives in 2012, according to sources from motherboard players. When asked about the company's upcoming Trinity schedule, AMD Taiwan declined to comment on unannounced products.

AMD started suffering from Llano APU supply shortages in July due to the yield issues and the company originally expected the supply status to return to normal in September. However, judging from the current situation, the sources believe the company's supply volume is unlikely to meet client demand through the end of 2011.

The sources estimated that the yield rate issue should be resolved in 2012, when Trinity launches."

A few weeks ago, a rumor regarding TSMC experiencing issues with NVIDIA’s 28nm manufacturing process for GPUs spread across the Internet. Not long after that rumor, a new rumor emerged that stated AMD would beat NVIDIA to 28nm. More information has now reached us in the form of a quote from AMD’s CFO Thomas Seifert who stated the following during the Q2 2011 Earnings Call:

“We also passed several critical milestones in the second quarter as we prepare our next-generation 28-nanometer graphics family. We have working silicon in-house and remain on track to deliver the first members of what we expect will be another industry-leading GPU family to market later this year. We expect to be at the forefront of the GPU industry's transition to 28-nanometer.”

With some talk of the new Radeon HD 7xxx series coming out as early as September, the statement that AMD has working silicon is a good sign that they are on track to deliver GPUs on the small 28nm manufacturing process. Whether they can beat NVIDIA to it; however, still remains to be seen. With that said, things are looking good for AMD’s GPU division. What are your thoughts on this, will NVIDIA pull a Hail Mary and get Kepler out of the gate before AMD can ramp up production of the new Radeons?